Excretory urography, computed tomography (CT) of the head, CT of the body, peripheral venography, and coronary computed tomography angiography (CCTA) were studied with either one or both iodixanol injection concentrations (270 mg Iodine/mL or 320 mg Iodine/mL). In the non-CCTA intravenous studies, diagnostic visualization ratings were good or excellent in 96% to 100% of the patients and a radiologic diagnosis was made in all of the patients given iodixanol. In the CCTA studies results were computed in terms of sensitivity and specificity compared to a standard of reference. The number of patients studied in each indication is provided below.
Excretory urography was evaluated in one uncontrolled, unblinded clinical trial in 40 patients, 20 given iodixanol 270 mg Iodine/mL and 20 given iodixanol 320 mg Iodine/mL, and in two randomized, double-blind clinical trials in 50 adult patients given iodixanol 270 mg Iodine/mL, 50 patients given iodixanol 320 mg Iodine/mL. Visualization ratings were good or excellent in all of the patients given iodixanol; a radiologic diagnosis was made in the majority of the patients. Confirmation of the radiologic findings by other diagnostic methods was not obtained.
CT of the head was evaluated in two randomized, double-blind clinical trials in 49 adult patients given iodixanol 270 mg Iodine/mL, in 50 patients given iodixanol 320 mg Iodine/mL. CT of the body was evaluated in three randomized, double-blind clinical trials in 104 adult patients given iodixanol 270 mg Iodine/mL, and 109 patients given iodixanol 320 mg Iodine/mL. In both CT of the head and body, visualization ratings were good or excellent in all of the patients given iodixanol; a radiologic diagnosis was made in the majority of the patients. Confirmation of the radiologic findings by other diagnostic methods was not obtained.
Peripheral venography was evaluated in two randomized, double-blind clinical studies in 46 adult patients given iodixanol 270 mg Iodine/mL. Visualization ratings were good or excellent in all of the patients given iodixanol; a radiologic diagnosis was made in the majority of the patients. The results were similar to those of the active control. Confirmation of the radiologic findings by other diagnostic methods was not obtained.
Iodixanol 320 mg Iodine/mL for CCTA was evaluated in two prospective, multicenter clinical studies in a total of 1106 adult patients. The patient population consisted of stable outpatients with chest pain or other symptoms suggestive of coronary artery disease, and no known history of coronary disease. All the CCTAs were done using 64 detector row CT scanners. Most of the patients received beta-blocker medication for heart rate control and nitroglycerin for vasodilation. Patients with irregular cardiac rhythm or heart rate above 100 beats per minute were excluded. The mean patient age was 57 years in the first study and 59 years in the second study. Both studies had more men than women (59% male in the first study and 51% male in the second study), and more Caucasian patients (88% in the first study and 78% in the second study) than Black, Asian, or other patients. The BMI range was 17 to 50 with a mean of 31 in the first study and a BMI range of 15 to 71 with a mean of 30 in the second study.
In the first study, 230 patients (906 vessels) were evaluable for efficacy using the reference standard of invasive coronary angiography. Seventy-five vessels (8%, in 49 patients) were evaluated as positive for ≥50% stenosis. The CCTA images were randomized and read by three blinded, independent readers; the coronary angiography images were interpreted by an independent, blinded reader. Assuming independence between vessels, the vessel-level sensitivity (95% CI) for assessing ≥50% stenosis was 76% (63, 86) for reader 1, 89% (79, 95) for reader 2 and 77% (65, 86) for reader 3. The vessel-level specificity (95% CI) was 85% (81, 89) for reader 1, 84% (81, 87) for reader 2, and 89% (86, 91) for reader 3. The vessel-level sensitivity and specificity for assessing ≥70% stenosis were similar.
In a second study, 857 patients were evaluable for efficacy. Patients were followed up for 12 months after CCTA and the reference standard was a composite of pre-specified clinical outcomes (death, major adverse cardiac event, or coronary revascularization). Seventy-six patients (9%) experienced one or more of the pre-specified outcomes over 12 months of follow-up. The sensitivity (95% CI) and specificity (95% CI) of a positive CCTA finding (≥50% stenosis at the patient level) to predict one or more of the pre-specified clinical outcomes was 95% (87, 99) and 87% (84, 89), respectively.